Blower unit



R. D. DELAMERE ,923,079 I BLOWER UNIT Filed Aug. 12, 1931 2 Sheets-Sheet l .l'rn nior. Fua/o/f lIDe/amerc 1933- R. D. DELAMIVERE 1,923,079

BLOWER UNIT Filed Aug. 12, 1931 2 Sheets-Sheet 2 Patented Aug. 22, 1933,

PATENT OFFICE BLOWER UNIT Rudolf D. Delamere, Toronto, Ontario, Canada Application August 12, 1931.

Serial No. 556,589

7 Claims. (Cl. 230-417) The'principal objects of this invention are, to provide a blower unit which may be very readily adapted tovarious types of furnaces for the purposeof accelerating combustion, or may be used in other places for controlling temperature.

A further object is to devise a construction of blower which will operate indefinitely and will not be detrimentally affected by temperature conditions. I

A still further object 'is to provide a structure in which the several elements of blower, motor and thermostatic control may be shopassembled ready for immediate installation.

The principal features of the invention consist in thenovel construction of the blower and its associated parts, whereby the impeller of the blower is supported entirely free of its surrounding casing by the bearings of its driving motor, and the motor bearings are protected against the effects of high temperature in the blower by means mounted on the motor shaft external to the blower casing.

In the drawings, Figure 1 is a side elevational view of the improved blower unit showing the motor in end elevation.

Figure 2 is an elevational view of the tmit showing the motor in side elevation.

Figure 3 is a plan view of the unit showing the blower casing partly in section.

Figure 4 is an enlarged elevational detail of the attachment for effecting the cooling of the motor, shaft.

Figure 5 is a mid-sectional view through the line 5-5 of Figure 4.

This application is a continuation in part of my application Serial No. 433,446 filed March 5, 1930 which resulted in Patent 1,826,748 granted October 13, 1931 and in which was disclosed the principal feature of the present application, namely, means for thermally insulating the motor from the blower.

In the operation of furnaces it has been found highly desirable to accelerate the natural draught by means of a blower interposed in the furnace flue and it is very desirable that a blower unit be provided which may be quickly and accurately placed in position. Further it is desirable to provide a blower unit which may be utilized in other relations and the accomplishment of these features is found in the accompanying structure.

The blower casing 1 is of an involute form. having the discharge end formed with a circular flange 2 around which is arranged an annular flange 3 extending at right angles therefrom. This latter flange is adapted to be bolted to a permanent flue structure while the flange 2 enters the flue opening in such structure.

The casing is formed with circular openings on either side which are closed by the flange plates 4 and 5 respectively.

The plate 4 is provided with a cylindrical tubular extension 6 into which the smoke pipe from a furnace or the draught pipe leading from a compartment from which the air is to be drawn, is connected.

The flange plate 5 is provided with a central circular opening 7. 0n the lower portion of the flange plate 5 is arranged a bracket 8 which extends horizontally from the blower casing directly below the central opening 7. This bracket is preferably cast integral with the plate 5, though of course it may be attached thereto if desired.

Mounted upon the bracket 8 is an electric motor 7 9, the base 10 of which is preferably insulated from heat and vibration by ferrules 11 resting on the bracket. The shaft of the motor 9 is preferably arranged in axial alignment with the opening 7 in the plate 5 and extends therethrough free of contact with the metal of the plate..

On the inner end of the shaft 12 is mounted the impeller 13.

The opening 7 provides an air duct surrounding the shaft so that the air drawn thereinto by the suction of the impeller forms a heat insulating stratum around the shaft. This inflow of air through the opening '7 is very greatly enhanced in the insulation of the motor from the heat of the blower by the provision of an arrangement of discs upon the shaft exterior to the blower casing.

Discs 14 and 15 are here shown mounted upon a ferrule 16 which encircles the shaft and is secured thereto by a lock screw 17. The ferrule presents an extended area to the shaft and absorbs heat therefrom which is in turn absorbed by the discs mounted thereon. The outer disc 15 is preferably perforated adjacent to the centre 100 with a plurality of holes 18.

The double disc structure is placed upon the motor shaft and spaced a short distance from the outer face of the plate 5 of the blower casing, thus forming an annular space 19 between 105 the inner imperforate disc 14 and the outer face of the plate 5 through which a constant flow of air is drawn'by the suction of the impeller. The disc 14 is thus partly insulated from the conduction of radiant heat from the plate 5 by the flow no of air therebetween and the continuous flow '1! air absorbs heat conducted to the disc 14 through the shaft. Further, it will be readily appreciated that heat rays emanating from the plate 5 of the blower casing will, to a considerable extent, be reflected back by the adjacent surface of the disc 14 which is preferably a white metal such as aluminum.

The action of centrifugal force causes the air to be thrown outward from between the discs 14 and 15 to be discharged directly into the comparatively cool surrounding atmosphere and this centrifugal action results in a volume flow of cool air being induced through the holes 18 in the outer disc 15 which acts effectively in cooling both discs and provides a very extended heat interchange with the surrounding atmosphere and thereby prevents the conduction of heat through the shaft to the bearings of the supporting and driving motor.

It will be noted that the construction defined provides for particularly eflicient heat exchange between the comparatively cool surrounding atmosphere and the extended surfaces presented by the paired discs, since cool air is introduced through the openings 18 in the outer disc at a point closely adjacent the centre and this cool air in being flung outwardly between the discs contacts with a considerable area presented by the discs beyond the actual openings and is immediately released into the free atmosphere carrying with it heatx absorbed from the discs. Moreover the inner disc of the pair being imperforate the centrifugal action originating between the discs cannot draw air from the space 19 between the inner disc and the blower casing to interfere with the inwardly induced flow of cooling air caused by the suction effect into the casing through the enlarged shaft opening 7.

It is found in practice that this very simple device provides an effective cooling attachment for a blower which is subjected to very high temperatures. The impeller is short coupled on the motor shaft and operates without the necessity of any hearings in the fan casing as the motor bearing is arranged comparatively close to the frame and the discs present a barrier or bafile stopping direct heat-radiation between the blower and electric motor.

The casing 1 is provided with a flanged bracket 20 which is arranged substantially in line with the transverse diameter through the axis of the blower and a thermostatic control 21 is adjustably mounted on said bracket by the threaded studs 22. The thermostat may be readily adjusted toward or from the blower casing so that it may be set to operate at a desired mean temperature, that is, the thermostatic adjustment may be regulated in accordance with the temperature of the blower.

The construction of the thermostat and the control box are quite common and the novelty and virtue of the invention consists in the arrangement of the thermostat in close association with the blower so that the heat emanating from the blower casing and partly tempered by the surrounding atmosphere is used to regulate the operation of the blower motor.

The casing 1 is here shown provided with two pairs of lugs 27 arranged on the bottom and adapted to form guides for a supporting frame for the blower when such is desired under certain local conditions where a permanent flue or chimney opening is not arranged so as to permit of .the support for the blower structure from such permanent flue.

It will be understood from this description that the device is extremely compact. It is easily and quickly assembled, there is a comparatively small amount of machine work required and the device may be readily shop assembled so that it may be easily and quickly installed. The device occupies very little space and by reason of thearrangement of the dual plates 4 and 5 the motor may be changed from right to left as may be desired.

What I claim as my invention is:

1. A blower unit for handling hot gases, comprising a blower casing having an opening separate from the intake and discharge openings, an electric motor mounted'close to said casing and having its shaft extending unsupported through the opening in the casing, an impeller mounted on said shaft within said casing, and means spaced between the casing wall and said motor to intercept heat rays radiated from the casing wall and to direct a flow of air over the casing wall inwardly around the shaft.

2. A blower unit for handling hot gases, comprising a blower casing having an opening in the side wall, an electric motor mounted close to said side wall and having its shaft extending through and spaced from the perimeter of said opening, an impeller mounted on said shaft within said casing, and means surrounding said shaft outside said casing and spaced between said motor and the casing wall to direct an annular flow of air inwardly between said means and the casing wall and around the shaft into the interior of the casing.

3. A blower unit for handling hot gases, comprising a blower casing having an opening in the side wall, an electric motor mounted close to said side wall and having its shaft extending through and spaced from the perimeter of said opening, 1

an impeller mounted on said shaft within said casing, and a disc of greater diameter than the opening in the casing wall mounted on said shaft outside said casing and spaced between the motor and the casing to bafiie heat rays radiated from the casing wall and to direct an annular flow of air inwardly between said disc and the casing wall and through the opening surrounding the motor shaft.

4. A blower unit for handling hot gases, comprising a blower casing having an opening in the side wall, an electric motor mounted close to said side wall and having its shaft extending through and spaced from the perimeter of said opening, an impeller mounted on said shaft within said casing, and a disc for white heat reflecting material of greater diameter than the opening in the casing wall mounted on said shaft outside said casing and spaced between the motor and the casing to baflle heat rays radiated from the casing wall and to direct an annular flow of air inwardly between said disc and the casing wall and through the opening surrounding the motor shaft.

5. A blower unit for handling hot gases, comprising a blower casing having an opening in the side wall, an electric motor mounted close to said side wall and having its shaft extending through and spaced from the perimeter of said opening, an impeller mounted on said shaft within said casing, and means mounted on the motor shaft between the blower casing and the motor adapted to baflle heat rays radiated from the blower casing and to dissipate heat conducted from the blower end of the shaft and to induce a flow of cool air through the motor.

6. A blower unit for handling hot gases, com

prising a blower casing having an opening in the side wall, an electric motor mounted close to said side wall and having its shaft extending through and spaced from the perimeter of said opening, an impeller mounted on said shaft within said casing, an imperforate disc of greater diameter than the opening in the casing wall mounted on the shaft outside said casing and spaced between the motor and said casing to battle heat rays radiated from the casing wall and to direct an annulus of air inwardly to the opening surrounding the shaft, and a disc mounted on the shaft and spaced between the aforesaid disc and said motor and having holes therethrough adjacent to the shaft to permit the inflow of air to the annular space between said discs to be discharged outwardly therefrom.

7. A device as claimed in claim 2 having a ferrule mounted on the motor shaft between the motor and the blower casing, an imperforate disc of thin metal mounted on the end of the ferrule adjacent to the blower casing, and a disc of thin metal mounted on the opposite end of said ferrule and having a plurality of holes therethrough arranged close to the ferrule.

RUDOLF D. DELAMERE. 

